[PATCH 5.4 029/408] net: ftgmac100: Fix Aspeed ast2600 TX hang issue

Greg Kroah-Hartman
2020-10-27T14:29:43Z

From: Dylan Hung <dylan_hung@aspeedtech.com>

[ Upstream commit 137d23cea1c044b2d4853ac71bc68126b25fdbb2 ]

The new HW arbitration feature on Aspeed ast2600 will cause MAC TX to
hang when handling scatter-gather DMA. Disable the problematic feature
by setting MAC register 0x58 bit28 and bit27.

Fixes: 39bfab8844a0 ("net: ftgmac100: Add support for DT phy-handle property")
Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/faraday/ftgmac100.c | 5 +++++
drivers/net/ethernet/faraday/ftgmac100.h | 8 ++++++++
2 files changed, 13 insertions(+)

--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1807,6 +1807,11 @@ static int ftgmac100_probe(struct platfo
priv->rxdes0_edorr_mask = BIT(30);
priv->txdes0_edotr_mask = BIT(30);
priv->is_aspeed = true;
+ /* Disable ast2600 problematic HW arbitration */
+ if (of_device_is_compatible(np, "aspeed,ast2600-mac")) {
+ iowrite32(FTGMAC100_TM_DEFAULT,
+ priv->base + FTGMAC100_OFFSET_TM);
+ }
} else {
priv->rxdes0_edorr_mask = BIT(15);
priv->txdes0_edotr_mask = BIT(15);
--- a/drivers/net/ethernet/faraday/ftgmac100.h
+++ b/drivers/net/ethernet/faraday/ftgmac100.h
@@ -170,6 +170,14 @@
#define FTGMAC100_MACCR_SW_RST (1 << 31)

/*
+ * test mode control register
+ */
+#define FTGMAC100_TM_RQ_TX_VALID_DIS (1 << 28)
+#define FTGMAC100_TM_RQ_RR_IDLE_PREV (1 << 27)
+#define FTGMAC100_TM_DEFAULT \
+ (FTGMAC100_TM_RQ_TX_VALID_DIS | FTGMAC100_TM_RQ_RR_IDLE_PREV)
+
+/*
* PHY control register
*/
#define FTGMAC100_PHYCR_MDC_CYCTHR_MASK 0x3f